See virtual worlds in the round

A GOLDFISH bowl in which 3D video images appear suspended in mid-air could help surgeons target tumours more precisely, air-traffic controllers prevent air accidents, and drug designers better understand the structures of promising molecules.

"On a 2D screen, a protein molecule looks like tangled spaghetti. But when it appears in our machine, you begin to fully grasp its 3D structure," says Gregg Favalora of Actuality Systems, which is behind the $40,000 display.

As Favalora walks around his display, a 3D computer model of a protein molecule hovers inside its smoky white soccer-ball-sized sphere. At the click of a mouse, the molecule disappears and is replaced by images of two airliners on a collision course in simulated 3D airspace.

Favalora is showing off his Massachusetts-based company's new product, Perspecta 1.9. It's the first 3D display that lets users view 3D moving images by walking all the way around it, view from on top or below, or zoom in and out in real time. It was unveiled last week at the Society for Information Display's annual exhibition in Boston.

A prototype version appeared in 2001 that could only show a low-resolution, static 3D image. Now, with the addition of dedicated graphics-processing hardware, the system is able to twist and turn images in real time at video rates.

Several applications have already emerged. Two oil companies, three medical centres and the US air force have bought or loaned Perspectas and are using them respectively to visualise slices of the Earth's crust from seismic data, human organs from MRI and CT scans, and squadrons of aircraft from radar data.

This is a big step forward from rotating a 3D computer image on a flat screen, Favalora says. Nothing beats being able to walk all the way around the object, view it from the top and zoom in whenever you want, he claims.